The Phanerozoic calendar of the history of the earth is composed of fundamental units called stages. A priority of the International Commission on Stratigraphy is to redefine these stages using a modern approach. This work presents a unique solution to the previously debated and diversified locations of the Campanian-Maastrichtian boundary, providing a precise correlation using the most accepted known time markers. The Campanian and the Maastrichtian are the last two stages of the Cretaceous System.

This volume includes a large amount of previously unpublished stratigraphical data. With the use of uncertainty margins for observations, established by comparison of results obtained by various experts using different approaches for the same stratigraphical tool, a new approach to stratigraphical information was employed. While most of the data have been taken from the recently rediscovered geological site at Tercis, France, data from other sections around the world have been considered. The section studied at Tercis is the best stratigraphical record on Earth for the period of several million years across the Campanian-Maastrichtian boundary.